Many down ballot positions are unopposed where I live. Of course, I think you only are talking about national seats.
The utility, then, is to note that safe seats operate similarly to unopposed seats especially when it comes to funding by national parties.
I’m not much of wine drinker myself, but I once did a chef menu with the wine pairing. Every two dishes, they’d bring out a new glass of wine. It was kind blowing how the would taste one way with the first dish and a completely different way with the second dish. I’m not sure I can tell the difference between a $12 bottle and $40 bottle, but in that one meal i understood two things: first, if you know what your doing, wine and food pairings can be magical and, second, I don’t know what I’m doing.